Beninger R J, Banasikowski T J
Department of Psychology, and Centre for Neuroscience Studies, Queen's University, Kingston ON, K7L 3N6 Canada.
Neurotox Res. 2008 Aug;14(1):57-70. doi: 10.1007/BF03033575.
Dopamine D(3) receptors (Drd3) have been implicated in the control of responding by drug-related conditioned incentive stimuli. We review recent studies of the effects of Drd3 antagonists or partial agonists on the control of self-administration of intravenous (IV) cocaine, IV morphine and oral ethanol on reward-rich and lean schedules, in reinstatement tests, on second-order schedules and on the acquisition and expression of conditioned place preference (CPP) and conditioned motor activity. For comparison, related studies where conditioned stimuli are based on nutritional reward also are considered. When self-administration depends more heavily on conditioned cues for its maintenance, for example on second-order schedules or lean ratio schedules, Drd3 antagonists or partial agonists reduce responding. Although data are limited, similar effects may be seen for responding for cues based on drugs or nutritional rewards. Drd3 agents also block the ability of conditioned cues to reinstate responding for cocaine or food. Published results suggest that Drd3 plays a more important role in the expression than in the acquisition of a CPP or conditioned motor activity. The mechanism mediating the role of Drd3 in the control of responding by conditioned incentive stimuli remains unknown but it has been found that Drd3 receptors increase in number in the nucleus accumbens during conditioning. Perhaps Drd3 participates in the molecular mechanisms underlying the role of dopamine and of dopamine receptor subtypes in reward-related incentive learning.
多巴胺D(3)受体（Drd3）与药物相关条件性激励刺激所控制的反应有关。我们综述了近期关于Drd3拮抗剂或部分激动剂对静脉注射（IV）可卡因、IV吗啡和口服乙醇自我给药控制的影响的研究，这些研究涉及丰富奖励和少量奖励时间表、复吸测试、二级时间表以及条件性位置偏爱（CPP）和条件性运动活动的获得与表达。为作比较，还考虑了以营养奖励为基础的条件刺激的相关研究。当自我给药对条件线索的维持依赖性更强时，例如在二级时间表或少量奖励比例时间表上，Drd3拮抗剂或部分激动剂会减少反应。尽管数据有限，但基于药物或营养奖励的线索反应可能也会出现类似效果。Drd3药物还会阻断条件线索恢复对可卡因或食物反应的能力。已发表的结果表明，Drd3在CPP或条件性运动活动的表达中比在获得过程中发挥更重要的作用。介导Drd3在条件性激励刺激控制反应中作用的机制尚不清楚，但已发现Drd3受体在条件作用过程中伏隔核中的数量会增加。也许Drd3参与了多巴胺和多巴胺受体亚型在奖励相关激励学习中作用的分子机制。
